Pollutant Concentrations

Air quality readings will be available hourly from 7am to 11pm. Air quality readings from 12am to 6am will be made available at 7am on the same day.

Readings on 24 Nov 2014

View reading for:

Region

24-hr Sulphur dioxide(µg/m3)

24-hr PM10(µg/m3)

1-hr Nitrogen dioxide(µg/m3)a

8-hr Ozone(µg/m3)

8-hr Carbon monoxide(mg/m3)

24-hr PM2.5(µg/m3)

North

2(1)

21(21)

41(-)

12(5)

0.3(3)

11(48)

South

16(10)

25(25)

35(-)

13(5)

0.6(6)

15(55)

East

6(4)

20(20)

9(-)

15(6)

0.4(4)

14(54)

West

7(4)

23(23)

20(-)

16(7)

0.5(5)

12(51)

Central

9(6)

20(20)

37(-)

21(9)

0.6(6)

11(47)

1-hr PM2.5 (µg/m3)b Readings on 24 Nov 2014

View reading for:

Time

1am

2am

3am

4am

5am

6am

7am

8am

9am

10am

11am

12pm

North

9

17

18

13

8

6

6

11

19

15

16

12

South

30

11

13

11

6

6

4

7

15

33

37

28

East

19

16

14

24

21

26

6

12

11

19

14

15

West

6

11

5

6

16

9

8

12

23

21

19

15

Central

13

13

10

16

4

10

6

10

6

12

11

14

Time

1pm

2pm

3pm

4pm

5pm

6pm

7pm

8pm

9pm

10pm

11pm

12am

North

19

19

12

12

11

8

8

6

9

3

7

-

South

22

25

12

13

18

6

1

3

13

17

8

-

East

16

18

18

20

10

11

9

13

10

7

5

-

West

9

11

18

9

5

19

4

13

16

19

8

-

Central

12

16

18

20

19

8

4

14

13

6

3

-

Note:a Sub-index for nitrogen dioxide is reported only when the 1-hr concentration equals or exceeds 1130 µg/m3.

b There is no sub-index for 1-hr PM2.5.

3-hr PSI Readings from 1am to 12am on
24 Nov 2014

Time

1am

2am

3am

4am

5am

6am

7am

8am

9am

10am

11am

12pm

3-hr PSI

54

55

53

52

51

51

39

38

43

54

58

59

Time

1pm

2pm

3pm

4pm

5pm

6pm

7pm

8pm

9pm

10pm

11pm

12am

3-hr PSI

57

56

56

55

53

52

39

35

37

44

40

-

Hourly updates of 3-hr PSI readings are provided from 7am to 11pm. The 3-hr PSI readings from 12am to 6am will be made available at 7am on the same day. The 3-hr PSI readings are calculated based on PM2.5 concentrations only.